I have been using the T70 design (with i5) for about 6 months or so now. I run ubuntu 17.10 and I have the lm-sensors package installed, where I can see an indication of the current temp at the top of my screen at all times. When putting it together I used arctic silver as I do with pretty much all of my builds, where I have never had significant issues. On the T70 things have been well the majority of the time, even at 100% cpu load I usually go between 70-80 degrees, which is acceptable to me. However, recently I started using blender for a project and the rendering has caused the cpu to reach 100 degrees as reported by lm-sensors. I Found that this is because blender makes use of both the cpu and the intel gpu when rendering.

This concerns me, has anyone else had this issue, is it to be expected? Is there any other type of cooler I can use? If not should I try to fix some bios settings to reduce the gpu clock speed or something?

Thanks for the suggestion, I will be sure to try out your paste suggestion. I have just used the cooler which was shipped along with the T70 board, Would you recommend that I look for a T500 or W500 replacement HSF and try that instead? Are there significant modifications of the case/rollcage needed if I go this route?

Which BIOS are you on? The newest version (180115) uses much more power than the previous ones, at least on windows. The coolest version is 170904 when activating ASPM for every PCIe device (this enables windows to use package C-state , but this version crashes when you wake up the machine from standby by opening the lid. I think linux has options to override BIOS ASPM settings (force ASPM), so any version between those mentioned should be fine for you. And will work with lid standby.

Then you should try undervolting (luckily, the T70 has these options in BIOS, undervolting tools for linux for newer intel processors are still in development), this will have a massive impact if it works fine with your processor. The i7 7700HQ T70's i heard of, including mine, allow more than 100mV of undervolting. wujstefan's 7820HQ unfortunately doesn't when using package C-states. YMMV. Always use offset values, not fixed values.

On the other hand, better cooling would of course be desireable. I just installed blender and run a test rendering. The CPU reached up to 100°C and throttled to 3.2-3.4 GHz. Probably some BIOS setting would allow us to use throttling at a lower temperature but what we really want is full speed at a lower temperature.

There's a fan assembly with optional water cooling available from 51nb but I'd prefer air cooling in a laptop. wujstefan suggested a fan mod along the lines of the elitebook 8740w mod descrebed in the notebookreview.com forum. And I'm thinking about routing the heatpipes to where the copper block is. We'll see.

Edit: I couldn't get the system to automatically throttle at a lower temperature yet, but by configuring the turbo ratio limit for 4 active cores down from 34 to 30, I could limit the system to a healthy 80°C under blender rendering load.

Have in mind that I am using Windows on this system for my CAD/CAM, and hence am supported by intel XTU to undervolt. However, this means having lots of other issues on this one

First of all - my i7-7820HK hits the 100C easily under full, real-life load generating CAM when left as-is. I wasnt able to undervolt the system in any bios older than 150118 (just as mentioned by NonesensE), and this mean that I have all the power-saving features disabled. However, power consumption when under heavy load stays the same, and this bios fixes many of the issues that W10 has with T70. It's the like trading something for something - my system is stable, but at a cost of consuming more power under light load / idle.

I was able to stably undervolt this thing by -0,15V on CPU, and -0,11V on GPU. Both are important to me - and to you as well - since both Blender and CAM software loads both CPU and GPU, and use all the resources you've got. I get 100% CPU and 100% RAM consumed when generating CAM.The results are actually better than expected; with turbo on (multiplier 34x on 4 cores) I get lower 80s, and with turbo off I get lower 60s. Pretty nice, especially when turbo is not needed (video streaming, gaming).

As for hardware, I guess here lies the problem. RBS mentioned testing another thermal compounds - since AS5 is not the best one, contains silver, and is not a put-a-rice-drop-and-go to apply. I can suggest using up a bit cheaper thermal comounds than Thermal Grizzly Cryonaut, because I've got on par if not better results with Arctic MX-4 (do not mistake it with Arctic Silver). Tested couple of top thermal compounds, with AS5 giving the worst (!) results considering MAX temps.

When examining the heatsink, I'm sure you noticed a huge block of copper welded to it - and this is the whole things' weak point. First of all, it's not a copper speed pulse mig weld (at least in my case), the surface is not perfect (I've polished mine), and I guess this is not a high-performance molybden-copper plate. This block is just necessary (since the CPU is placed much lower in the chassis than in original T61), and this will cause problems. I think I will try to reproduce a bit different heatsink, and will try to dissipate the heat from the heatsink at lower level, just as mentioned by NonesensE - this may not be as successfull as in 8740w, but I hope to get some reasonable results.

Last edited by wujstefan on Thu Feb 15, 2018 9:58 am, edited 1 time in total.

1. I'll have to find a tube of thermal epoxy first. It seems unavailable in stores here, so I may have to order overseas. I have a few heatsinks from dead laptops, from which I can harvest some copper plates (and hopefully some heatpipes).

2. My X61 T7500 is dead, so my only plaything is a recently-relegated-to-backup X220 (which served me well for 3 years), as I obtained an X220 i7 recently.

I don't own a T70 board, but if you want a T61p fan I have a couple new NOS fans for $30. I prefer these to the T500 as they have a bigger heatsink and are designed to cool the more powerful nVidia graphics.

Again a disclaimer because I don't own one, but in general I don't like that the I-series has graphics in the same card as the cpu, a good idea if trying to make computers smaller, but bad for cooling.

On my own testing using t61/t61p boards I found arctic silver to work extremely well, but a lot depends on how it is applied. Since these are stamped metal heatsinks, not milled, you need a paste that will flow to fill the gaps and a good fitment, and I don't doubt other pastes may work better, but I like to stick with what works and compared to lenovo factory paste, the arctic silver 5 runs about 5-7 C degrees cooler on a NOS t61 board with 2010 nvs140m GPU chip and penryn cpu using the NOS t61p heatsink.

Of course environmental factors play a big part when it comes to temp.

ps. don't know if this is relevent, but I know some modding of the heatsink is needed to fit the dual dies of quad core cpu chips so make sure your i5 chip is getting good flush contact with whatever heatsink you may use.

Since these are stamped metal heatsinks, not milled, you need a paste that will flow to fill the gaps and a good fitment, and I don't doubt other pastes may work better, but I like to stick with what works and compared to lenovo factory paste, the arctic silver 5 runs about 5-7 C degrees cooler on a NOS t61 board with 2010 nvs140m GPU chip and penryn cpu using the NOS t61p heatsink.

This is unfortunately not the case. T70 has a welded piece of machined (milled) copper.
Generally cooling system of T70 is a bit lame, but is the best you could do out from a standard cooling system...

As for the other part, I've found T61p fan far superior to any other. Most possibly because of 35W power hog that sits under T61p's hood and needs to be cooled. I am not a great fan of AS5 however, since applying it is not straightforward, and non-silver thermal compounds have developed much in the last couple of years.